Electric switch of the tumbler type



Dec. 29, 1931.

J. B. TUCKER ELECTRIC SWITCH OF THE TUMBLER TYPE Filed Aug. 5, 1926 i #2 wk 2% ll "r al Patented Dec. 29, 1931 UNITED STATES JOHN BRISTOW TUCKER, OF BIRMINGHAM, ENGLAND ELECTRIC SWITCH OF THE TUMBLER TYPE Application filed August 5, 1926, Serial No.

The object of this invention is to simplify the construction of the mechanism of an electric switch of the tumbler type embodying a quick make and break mechanism, and means 5 for positvely operating the switch in both directions in the event of the spring failing to act or act efficiently, the essential feature of the invention residing in dispensing with the ordinary pin and slot connections or their mechanical equivalents which usually obtain between the dolly or tumbler and the contact arm, or a part connected therewith. In the ordinary constructions referred to, the embodiment of a positive operating mechanism has involved the addition to the switch mechanism of certain parts, such as laterally projecting pins or lugs, which are disposed within or operate in conjunction with slots or apertures formed in the co-acting part, by means of my present invention I dispense with such additional parts or mechanisms.

My invention consists in the utilization of the lower end of the dolly without any additions or any substantial alteration, as the means for effecting the positive action in both directions of the contact arm, the said dolly also functioning to limit or restrict the throw of the contact arm in that the operative and generally parallel outer faces of the lower end of the dolly form a sliding contact with projections, lugs, or walls, secured to or formed integral with the contact arm, where by, initially, the dolly or tumbler serves to positively operate the contact arm in either direction, and subsequently forms a motion limiting stop by the abutment of the dolly or tumbler against one of the said projections, lugs, or walls of the contact arm, said abutment being made by the opposite face of the dolly or tumbler to that effecting the positive action as a result of the quick make and break action of the spring of the switch mechanism.

In order that this invention may be clearly understood and readily carried into practice, reference may be had to the appended explanatory sheet of drawings, upon which Figure 1 is a vertical sectional elevation of an electric switch constructed according to the present invention.

127,220, and in Great Britain May 13, 1926.

Figure 2 is a similar view, illustrating the switch components in a substantially midway position in their operation.

Figure 3 is a vertical sectional elevation corresponding to the Figure 2, taken in a plane at right-angles to that utilized in the said Figure 2.

Describing now a convenient means of carrying the invention into effect in connection with an electric tumbler switch of the kind wherein the lower part a of the dolly or tumbler a co-operates with an oscillating member 6 secured to but insulated from the contact carrying arm a: The lower portion a of the dolly or tumbler a which is of the usual configuration projects within a sidewalled or side-bounded space or gap formed in the upper end of the oscillating member (see particularly Figure 2), that is, between the opposed faces of the projecting sections (indicated by reference letter 1)) of the oscillating member when the said member is in the form of a bent strip of substantially U- shape. The upper ends of this member are turned inwardly or formed with projections 5 adapted to co-operate with the parallel faces of the lower portion a of the dolly or tumbler, one or other of the said faces being adapted to contact with one of the faces of the dolly or tumbler, the respective face in contact at any one time depending, of course, upon the position of the dolly or tumbler, that is, whether the dolly or tumbler is in a position for making or breaking the circuit. Thus in the event of the failure of the quick make-and-break spring-controlled mechanism, one or other of the faces of the lower portion of the dolly or tumbler will contact with one of the inwardly turned sides or walls 5 of the oscillating member, and by pressing thereupon will move the contact arm or blades into the desired positon. When the dolly or tumbler a has been moved into the said position, it will be appreciated that the opposite acting face of the dolly or tumbler will be in contact with one of the projections or inwardly turned sides or walls 6 of the oscillatory member, and hence will serve as a means for limiting the degree of angular motion permitted to the contact arm or blade I) 0, when the switch is operating normally under its spring control. The said sides or walls 6 may be formed on one side only of the U-shaped sheet metal member 7) whlch is secured to and forms part of the contact arm, or the said sides or walls may be formed on both of the arms of the U- shaped rocker, as shown: in practice the latter construction would be favoured, in that 10 by incorporating a pair of projecting sides or walls, the pressure applied thereto would be distributed and thereby increase the mechanical efiiciency of the switch.

It will be appreciated that an electric tumbler switch constructed as hereinbefore described is efiicient in operation and ensures a positive actuation of the switch mechanism in the event of the failure of the spring-con trolled quick make-or-break mechanism, and, in addition, by reason of the elimination of the necessity for the provision or projections, pins, or lugs on the dolly or tumbler, permits of a reduction and an economy in the cost of manufacture of electric switches of the kind hereinbefore referred to.

l/Vhat I claim as my invention and desire to secure by Letters Patent is In an electric switch, a pivoted rockable dolly, a pivoted rockable switch arm, the pivotal axes of said dolly and said switch arm being disposed in parallel spaced relation, an arm on the dolly overlying the switch arm, and lateral projections on said switch arm to either side of said dolly arm whereby 5 the side edges of said dolly arm are adapted for engagement with the inner faces of said lateral projections to eflect rocking of the switch arm, said projections having end edges disposed between the pivots of said dolly and said switch arm adapted for engagement with the side edges of said dolly arm to limit rocking movement of the switch arm.

In witness whereof I have hereunto set my hand.

JOHN BRISTOVV TUCKER. 

